This invention is directed to therapeutic procedures for a patient's heart and to instruments and systems for such procedures. The invention is particularly suitable for treating a patient suffering from the symptoms of congestive heart failure (CHF), and particularly to those CHF patients exhibiting mitral valve regurgitation (MVR) and/or those exhibiting intraventricular conduction delay with resulting disturbance of the synchronous right and/or left ventricular contractility.
There are over five million patients in the United States suffering from CHF and there are more than seven hundred thousand new cases of CHF each year. For many of these patients medical therapy is not very successful. Recent trials have shown that a significant number of CHF patient's benefit from percutaneous ventricular pacing where pacing leads are introduced percutaneously and advanced within the patient's vasculature until the leads are disposed within the patient's coronary sinus. However, ventricular pacing has not been found successful for a significant number of CHF patients for a variety of reasons. For example, in a number of procedures the coronary sinus cannot be cannulate due to dilated cardiomyopathy (the deformity of the heart which accompanies CHF) and, even if the coronary sinus is cannulated, the pacing leads can become displaced rendering them ineffective.
With many CHF patients, their ventricular ejection fraction is reduced due to mitral valve regurgitation (MR) which may also result from dilated cardiomyopathy. The MR in turn can exacerbate the cardiomyopathy leading to a worsening of the MR. The MR can also be the result of torn cordae tendenae which extend from the valve leaflets to the papillary muscles, preventing complete closure of the valve.
Surgical procedures for mitral valve repair for MR typically involves valve support ring at the base of valve. Recent advances in mitral valve repair include securing together the free edges of the mitral valve leaflets by sutures, staples and the like, commonly called “Bow-Tie” or “edge to edge” techniques. These procedures usually involve open heart surgery, including cardiopulmonary bypass and a sternotomy, although more recently suggestions have been made of performing these procedures with minimally invasive and percutaneous techniques which can reduce the morbidity of such procedures. Percutaneous procedures impose difficulties in instrument design because the instruments for such procedures must be long enough to extend from the entry location on the patient's leg to the interior of the patient's heart chamber, and they must have small enough profile and have sufficient flexibility for advancement through the patient's vasculature into the patient's heart chamber. Additionally, the instruments for such percutaneous procedures must also be able to accurately locate the operative distal ends of such instruments at a desired location within the chambers of the patient's beating heart and be strong enough to perform the required functions.
Techniques for Bow-Tie repair of mitral valves have been mentioned in the patent literature, but specific instruments for such techniques are not yet commercially available.